Edging apparatus

ABSTRACT

An edging apparatus edges a wood board to achieve a desired rounding effect under a rounding rule of the lumber industry. A positioning apparatus positions and holds two edging saws, and the positions of the saws are initially controlled by an operator who selects initial cut positions. Input data, including board length and thickness parameters and the initial cut positions are generated by input devices and a computer is responsive to the input data for computing the best cut positions of the saws. In making this computation, the computer takes into consideration the rounding rule and, according to predetermined criteria, the computer selects best cut positions that will produce an edged board whose measurement exceeds a whole board foot measurement by a desired fraction of a board foot. Adjustment input may be provided to adjust the size of the desired fraction of the board foot. The computed best cut positions are then transmitted as output from the computer so that the saws may be positioned in accordance therewith. Length trim markers are positioned in front of the saws to mark the trim length of the board before it is edged. Thus, length trim and edging decisions may be made at the same time by the same operator before edging or trimming the board. In one form, the thickness of all boards is assumed to be one inch, as is the custom of the industry.

This application is a continuation of application Ser. No. 850,225,filed 4/10/86.

FIELD OF THE INVENTION

The present invention relates to an edging apparatus and particularlyrelates to an edging apparatus for hardwood boards that computes bestcut positions for the edging saws based on the rounding rule that isused when measuring the wood.

BACKGROUND AND SUMMARY OF INVENTION

An edger is an apparatus that is used to cut lengthwise edges on a woodboard and it typically includes a pair of saws to cut the lengthwiseedges. Numerous edging devices have been developed that optimize thephysical size of the edged board. These prior devices typically seek toedge the board in order to obtain the largest board possible, and theproblem with these devices as applied to hardwood is that they ignorethe rounding rule used to price hardwood lumber. In accordance with oneaspect of the present invention, an edging apparatus is provided thatmakes edging decisions based on the rounding rule of the hardwood lumberindustry in the United States.

The rounding rule basically provides that the measurement of all boardsshall be rounded to the nearest whole board foot. For example, a boardhaving a measurement of 4.4 board feet would be rounded to four boardfeet, and 4.6 board feet would be rounded to five board feet. Hardwoodboards are cut to standard lengths and thicknesses, but the width of theboard may be cut to any random size. Thus, the width of the board iscritical in determining the number of board feet in a particular board(A board foot is the equivalent of a board that is 1" thick, 1' wide and1' long). In view of the rounding rule, an edger that merely maximizesthe size of the board is wasteful in a sense. For example, it would bewasteful to edge a board so that it measured 4.4 board feet. It would bepreferred to edge the board so that it measured 3.6 board feet. A boardthat measures 3.6 board feet will be rounded to four board feet, thesame as a board measuring 4.4 board feet, and the value of the twoboards is the same. But, when the board is cut to 3.6 board feet, asopposed to 4.4 board feet, a greater volume of valuable wood chips areproduced. Also, in edging the board to achieve 3.6 board feet, asopposed to 4.4 board feet, it is less likely that the board will bedegraded for leaving too much wane or will require a second edging.

In the United States, the procedure for tallying hardwood is todetermine the length and width of a board and determine an assumednumber of board feet based on a one inch thickness assumption. Theassumed board foot measurement is rounded to the nearest whole boardfoot, and later such measurement is corrected for thickness. Forexample, if a board is one-half inch thick, the assumed board footmeasure is divided by two, and the result is the actual board footmeasurement by which the board is sold.

In actual practice, a tallying stick is used to measure the boards. Thetally stick is a ruler with numerous parallel scales; each scale markedin board feet for a particular length board. For example, to measure afourteen foot board, the person taking the tally places the tally stickacross the width of the board, locates the scale for fourteen feet andreads a board foot measurement directly from the scale. The tally stickhas already performed the multiplication, in a sense. Later when thetallying is complete for a stack of boards having equal thickness, themeasurement for the entire stack is multiplied or divided by a factor tocorrect for the thickness of the board. From the above discussion, itwill be appreciated that, in practice, the industry is rounding theboard area measurement and then multiplying by board thickness, eventhough the tally stick is scaled by board feet, a measurement of volume.As used herein the concept and terminology of "rounding a board foot"measurement is broadly construed and includes the rounding system usedby the United States hardwood industry.

The present invention provides an ability to edge a board so as toachieve a desired effect taking into consideration the rounding rule.

In accordance with one form of the present invention, an edgingapparatus includes saws for edging a board and a positioner forpositioning and holding the saws. A selector is used by an operator toselect initial cut positions by the saws and input apparatus generatesinput data corresponding to board length and initial cut positions. Inthe preferred embodiment, the input apparatus includes sensor means orfeedback means connected to the positioner for directly generating datarelating to initial cut positions, and a keyboard is provided on whichthe operator inputs the length of the board. A computer is responsive tothe input data for at least multiplying the board length by a widthfactor corresponding to the initial cut positions to produce a computedsignal. The computed signal is produced as an output and the saws arepositioned based on the computed signal. It is preferred to mechanicallyposition the saws based on the computed signal, but an operator decisionalso could be made based on the computed signal, and the saws would bepositioned accordingly. In the latter case, information based on thecomputed signal is shown on a display, and the operator reads thedisplay, makes a decision and manually positions the saws. In accordancewith another form of the present invention, an edging apparatus iscontrolled by an operator and has two saws for edging a wood board thatis priced by the whole board width in accordance with the rounding ruleunder which fractions of a board are rounded up or down. The edgingapparatus includes a positioning device for positioning and holding thesaws, and through a selection apparatus the operator selects initial cutpositions for the saws. Input devices generate input data that includesboard length and thickness parameters and the initial cut positions. Inone embodiment, a keyboard is used to provide the board length andthickness parameters and a position feedback circuit is used to providedata on the initial cut positions if, however, the apparatus is designedto assume a one inch thickness, the operator need only keypunch lengthdata. In such case the thickness factor of "1" is incorporated in acomputer program stored in a memory and such memory may be considered aspart of the input device providing input data. A computer is responsiveto the input data for computing the best cut positions for the sawsbased on the rounding rule. The best cut positions are computed toproduce an edged board whose measurement exceeds a whole board footmeasurement by a desired fraction of a board foot, and an output deviceis provided for outputting the computed best cut positions so that thesaws may be positioned in accordance therewith.

It will be noted that the present invention provides that the best cutpositions are determined so that the edged board exceeds a whole boardfoot measurement by a desired fraction thereof. In many cases, thedesired fraction will be slightly more than 0.5, such as 0.6 board feet,so that the board will always be rounded upwardly. However, in othercases, an operator may not wish to take advantage of the rounding rule.In some cases, saw mills have built up a reputation for measurementgenerosity. That is, customers may buy from a particular saw millbecause he feels that the lumber received from that mill is usuallyrounded down rather than up. In order to maintain this reputation ofgenerous measurements, an operator may prefer to choose the fraction sothat it is more than zero but less than 0.5. For example, he may wish tohave each board measure 0.2 board feet over a whole board foot and wouldthus choose the fraction to be 0.2 board feet. In order to achieveflexibility and accommodate different saw mills, one embodiment of thepresent invention provides an adjustment means that is operable throughthe computer to adjust the size of the desired fraction of a board foot.In this manner, an operator may make an intelligent decision as towhether his boards should be cut to a size that will cause theirmeasurements to be rounded up or down.

In the above discussion concerning the rounding of board footmeasurements, it will be recalled that such rounding occurs in the tradebefore the measurement is corrected for actual thickness. For example,suppose a 1/4" board measured slightly over 81/2 board feet on a tallystick. Under industry practice, over 81/2 is rounded to 9 and thendivided by four to correct for thickness. Thus, the board wouldcontribute 21/4 board feet in measurement for the tally of a stack of1/4" boards. The computer in the preferred embodiment uses the 1"thickness assumption that is used in the industry, but the presentinvention could accommodate other rounding rules or changing roundingrules by simply modifying the computer's programming. Except as setforth in the claims, it is not intended to limit the invention to anyparticular rounding rules.

When the computer is calculating the best cut positions, it must knowthe board thickness and length or in the case of assumed one inchthickness it must know board length. In the past, the length trimdecision was usually made independently of the edging decision and thetwo decisions were usually made in different places by different people.This system made it difficult or impossible to make truly intelligentedging and trim decisions that took into consideration the roundingrule. The present invention solves this problem by providing a lengthtrim marker that marks the board with trim marks indicating where theboards should be trimmed to achieve a desired board length based onboard length input data. The length trim markers are positioned in frontof the saws and the board is marked before it is edged. In this manner,the length trim and edging decisions may be made at the same time by thesame operator prior to edging or trimming. Alternatively, an automaticspray marker which sprays digits designating length may be used as trimmarkers. This marker indicates digitally the length to which the boardis to be trimmed.

In accordance with another aspect of the present invention, theapparatus further includes judgment means associated with the computerfor making a judgment as to whether the best cut positions should befurther apart or closer together than the initial cut positions in orderto achieve the desired fraction of a board foot when the board is edged.The judgment in many cases will be to always choose a best cut positionin which the cut positions are spaced closer together than the initialcut positions. In another embodiment, the best cut positions may bechosen to be those that are nearest the initial cut positions thatachieve the desired fraction of a board foot. Also, an override isprovided so that the operator may override the decision of the judgmentmeans as to whether the best cut positions should be further apart orcloser together than the initial cut positions, and a further manualoverride control is provided so that the operator may manually set theposition of the saws independently of either of the computed best cutpositions.

In accordance with yet another aspect of the present invention, afurther embodiment provides a preview table for receiving boards andlasers forming laser lines representing saw lines on the preview table.Positioning apparatus and controls are provided for moving the lasersand laser lines on the preview table to position the laser lines on theboard in desired initial cut positions, and initial cut position data isgenerated by feedback circuitry corresponding to the initial cutpositions selected by the operator using the lasers. Based on theinitial cut position data, and the other input data, the best cutpositions are calculated and an output signal is generated thatcorresponds to the best cut positions. A control mechanism is responsiveto the output signal to position the saws in such best cut positions. Inthis manner, the lasers and the saws operate independently, and becauseof this independent operation, the lasers may be used to select best cutpositions for a new board while the previous board is being edged.

In the apparatus utilizing a preview table and a plurality of lasersassociated with the preview table, the length trim selection may also bemade at or adjacent to the preview table. In accordance with anotheraspect of the present invention, a plurality of lasers form a pluralityof laser trim lines across the preview table to indicate possiblestandard lengths to which the board may be trimmed, and a plurality oftrim markers are aligned with the laser trim lines for selectivelymarking the boards at positions corresponding to the laser trim lines.In the preferred mode, an infeed table is positioned downstream from thepreview table and upstream from the saws. A transfer mechanism transfersthe boards from the preview table to the infeed table, and as the boardsare transferred, the boards are marked by the trim markers.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention may best be understood by reference to thefollowing Detailed Description of preferred embodiments when consideredin conjunction with the Drawings in which:

FIGS. 1a and 1b represent two hardwood boards prior to edging;

FIG. 2 is a plan view of an edger having an infeed table in front ofedging saws;

FIG. 3 is an end view of the infeed table also showing a trim marker andlasers that are slaved to the saws;

FIG. 4 is a side view of the infeed table and the trim markers;

FIG. 5 is an operational block diagram depicting the operation of theedger shown in FIGS. 2, 3 and 4;

FIG. 6 is a block diagram of the control system for the edger;

FIG. 7 is a plan view of a second edger having an infeed table and apreview table with edge lasers mounted adjacent the preview table andsaws positioned adjacent the infeed table;

FIG. 8 is an end view of the infeed table and preview table showing trimmarkers positioned between the two tables;

FIG. 9 is a side view of the preview table showing trim markers andlasers aligned with the trim markers;

FIG. 10 is an operational diagram for the edger shown in FIGS. 7, 8 and9; and

FIG. 11 is a block diagram of the control system for the edger of FIGS.7, 8 and 9.

DETAILED DESCRIPTION

Referring now to the drawings in which like reference charactersdesignate like or corresponding parts throughout the several views, apair of unedged boards 10 and 11 are shown in FIGS. 1a and 1b that aremarked to illustrate the edging of the boards. In FIG. 1a, the board 10is marked with a dotted line 12 that indicates the lines along which anoperator would select to edge the board. In this case, the operator hasselected what he considers to be the optimum position for edging theboard 10. Under the grading rules for hardwood boards, a certain amountof wane may be left on the board. In this case, wane has been left inthe area designated by the character 14 and it covers approximatelyone-third of the length of the board. If board 10 were to be manuallyedged, it would be edged along lines 12 and wane would be left in thearea 14. If the operator made a poor edging decision and left too muchwane, the board will be degraded or it is necessary to re-edge theboard.

In FIG. 1b, a second board 11 is shown with the solid edging lines 16representing one choice for edging the board and the dotted edging lines18 representing a second choice for edging the board. These two choiceswere made taking into account the rounding rule that is used formeasuring hardwood boards. In measuring hardwood boards, the board isfirst assumed to have a one inch thickness, and then anything overone-half of a board foot is rounded up, anything below one-half of aboard foot is rounded down; and boards whose measurements includeexactly one-half of a board foot are rounded up half of the time anddown half of the time. After rounding, the measurements are correctedaccording to the actual thickness of the board. In the example shown inFIG. 1b, the edging choices have been depicted to take advantage of therounding rule. The edging lines 16 represent interior edging positionsand the edging lines 18 represent the exterior edging positions. Forexample, if the board is edged along line 16, the board will measureslightly greater than 9.5 board feet and will be rounded to ten boardfeet. If the board is edged along the line 18, it would measure slightlygreater than 10.5 board feet and would be rounded to eleven board feet.If the board is edged anywhere between lines 16 and 18, it will berounded to ten board feet. Thus, to maximize the value of the board 11,it would be preferred to edge the board along line 16. In this manner,the possibility of leaving too much wane and having the board 11degraded is minimized. In fact, in this example, edging along lines 16would leave no wane. The portion of the board that is removed during theedging produces valuable wood chips and, thus, the total value obtainedfrom the rough board 11 is increased by edging the board along theinterior positions defined by edging lines 16. If the board were edgedalong the edging lines 18, too much wane would be left and the boardwould be degraded or would require re-edging.

In the apparatus of the present invention the rounding rule is takeninto consideration to achieve a desired effect. As previously mentioned,it may not be desirable in every case to take advantage of the edgingrules. In some cases, a saw mill operator may desire to edge his boardsso that the edging rules actually take advantage of him in that hisboards are cut so that their measurements must be rounded downwardly.

An edger 19, constituting one embodiment of the present invention, isshown in FIGS. 2, 3 and 4. FIG. 2 is a plan view of an infeed table 20of the edger 19. FIG. 3 is an end view of the edger 19 showing an arrayof trim lasers 22 and trim markers 24, and FIG. 4 is a side view of theedger 19 also showing the trim lasers 22 and the trim markers 24.Referring to FIGS. 2, 3 and 4, it will be appreciated that the infeedtable 20 is equipped with chains 26 mounted on the drive sprockets 28that are used to move the wood boards, such as boards 10 and 11, in atransverse direction with respect to the infeed table 20. The boards 10are generally positioned in an orientation perpendicular to the chains26 and the chains 26 are raised by chain lifts 27 which are mounted onair bladders 29 and move the boards 10 onto the infeed table 20. Oncethe board 10 is positioned over the infeed table 20, the chains arelowered and rollers 30 support the board. With the board on the rollers30, the operator rough sets the board by hand in a proper position onthe rollers 30 so that it will be positioned generally perpendicularlyto the rollers 30 and the chains 28.

A saw chamber 31 is positioned adjacent to the right side of the infeedtable 20, and a pair of edging saws 32 are mounted within the chamber31. A pair of lasers 34 are slaved to the saws 32 and produce a pair oflaser lines 36 projecting down the length of the infeed table 20. Thelaser lines 36 represent the edging lines or saw lines that will beproduced when the board on the infeed table is fed into the saw chamber31. Feed rollers 35 are also mounted within the chamber 31 for feeding aboard toward the saws 32, and a control panel 38 is provided on the leftend of the infeed table 20 for controlling the various operations of theedger 19. The control panel 38 is conventional in design and includes adisplay 40, a key pad 42, a joy stick 44 and lighted push buttons 46.The control panel 38 is interfaced with a computer which will behereinafter described in greater detail. The joy stick 44 is used tomanipulate the position of the saws 32 and the slaved lasers 34, and thepush buttons 46 provide specific purpose actuation signals as willhereinafter be described in greater detail.

Referring to FIGS. 3 and 4, there is shown an array of trim lasers 22that project laser lines across the infeed table 20 in a transversedirection. The lasers 22 are positioned to mark standard board lengthsto which a rough board may be trimmed. By observing the laser linesprojected from lasers 22, the operator may position a board for trimmarking. A plurality of trim markers 24 are aligned with the lasers andare operable to mark boards on the infeed table 20 along the laser linesfrom lasers 22. An individual trim marker 24 is best shown in FIG. 3.The trim marker 24 includes a telescoping arm 50 that is preferably apiston and cylinder that extends and retracts a marking wheel 52. Oncethe arm 50 is fully extended, a second piston and cylinder set 54retracts and causes the arm 50 to pivot about a pivot point 56. In thismanner, the marking wheel 52 is forced downwardly. As the arm 50retracts, the piston and cylinder 54 continues the downward pressure onthe marking wheel 52 so that it will run across a board when it is onthe infeed table 20. The dotted arm 58 designates the position of thearm 50 after it is fully retracted and after it has marked a board onthe infeed table.

An operation block diagram is shown in FIG. 5 that illustrates thefunction of a computer 66 in controlling the edger 19. The chains 26 arepreferably controlled through the special purpose buttons 46 in aconventional fashion. Once the board has been manually positioned on theinfeed table, the operator observes the laser lines 36 and using the joystick 44 moves the saws 32 and the lasers 34 into a desired positionwhich is referred to herein as the initial cut position. The joy stick44 operates a servo positioner 60 for the saws 32 and the lasers aremoved by virtue of the fact that they are mechanically slaved to thesaws. A position feedback circuit 62 feeds saw position data to thecomputer 66 and, thus, the computer 66 constantly monitors the positionof the saws 32. After the operator has positioned a board 10 in adesired position on the infeed table 20, the desired board thickness andboard length must be input to the computer 66 through inputs 68 and 70.The board thickness input 68 may be a mechanical device that actuallyphysically measures the board as it is resting on the infeed table 20,but it is preferably information that is provided to the computerthrough the key pad 42 on the control panel 38. Likewise, the boardlength input 70 is provided through the key pad 42 by the operator. Theboard thickness input may also be an assumed value of one inch which isincorporated into the computer program of computer 66.

The length to which a particular board 10 will be trimmed is determinedby the operator while the board 10 is resting on the infeed table 20.This decision is aided by the array of lasers 22 which show the operatorwhere the board may be trimmed in terms of standard lengths. Once theboard length and thickness have been given to the computer 66 and theoperator has set the saws 32 to an initial cut position, the computeinput 72 is provided to the computer 66. Again, this input may beprovided to the computer through a special purpose button 46, or thecompute signal may be given through the key pad 42. When the computeinput 72 is provided, the computer 66 will calculate the board footmeasurement of the board after it is edged. In the preferred mode, thecomputer will follow the rounding rules that first assume a one inchthickness. Once that measurement has been determined, the computer 66will then select a best cut position based upon predetermined criteriawithin the computer. In the preferred and simplest embodiment of theapparatus, the computer will determine the best cut positions that arenearest the initial cut positions, but narrower than the initial cutpositions. For example, if the board had a measurement of 9.8 board feetwhen the saws were placed at the initial cut positions, the computer 66would select best cut positions that would produce a measurement ofslightly greater than 9.5 board feet. In this manner, the board will beedged to provide the smallest possible board that will still be roundedup to ten board feet. After the compute input 72 is given, the computerwill produce a position output on line 74 that will actuate the servopositioner 60 to move the saws to the best cut positions. Also, thelasers 34 will move to show the operator the best cut positions selectedby the computer 66. If the operator agrees with the selection made bythe computer 66, a trim command may be given through the key pad 42 anda trim output will be produced by the computer 66 on line 76 to the trimmarkers 24. The operator has previously given the computer 66 theselected board length and the appropriate trim markers 24 will beactuated to mark the board accordingly. If the operator is not pleasedwith the best cut positions selected by the computer, a manual overrideinput 78 may be provided to the computer 66 by the operator through thekey pad 42 or through the special purpose buttons 46. Once the manualoverride input 78 is given, the saws 32 are placed in any positiondesired by the operator using joy stick 44.

In order for the computer 66 to accurately position the saws 32, thecomputer 66 must have a saw kerf adjustment input 80 so that the edgingdecision takes into consideration the width of the saws 32 when they arepositioned. The saw kerf adjustment input 80 is provided to the computer66 through the key pad 42.

An offset adjustment input 82 is also provided to the computer 66. Thisoffset adjustment input 82 determines the fraction of a board footmeasurement that the computer 66 will attempt to obtain. For example, if0.65 board feet were input to the computer 66 as the offset adjustmentinput 82, the computer 66 would always select best cut positions thatwill provide a 0.65 fractional board foot. For example, if an initialcut position selected by an operator produced a ten board footmeasurement, the computer 66 would select best cut positions that wouldproduce a 9.65 board foot measurement. Alternatively the computer 66could be programmed to make a judgment to select one of several best cutpositions. In one form, it could select the nearest board footmeasurement that had a 0.65 fractional board foot measurement. Forexample, if the initial cut positions produced a board measurement of10.4, the computer would select best cut positions to produce a boardfoot measurement of 10.65. If this were not an acceptable position, thecomputer 66 could be prompted to select the next smaller or more narrowbest cut position, and it would select the best cut positions thatproduced a 9.65 board foot measurement. In another form, the computer 66selects the wider best cut position if it is within a selected range ofthe initial cut positions, else it selects the narrower best cutposition. The foregoing are intended only as examples of the type oflogic that may be programmed into computer 66 to select best cutpositions. In each case, the boards are edged in order to produce adesired effect in accordance with the rounding rule that is used in thehardwood lumber industry. In the preferred embodiment, the computer 66is programmed to assume a one inch thickness and calculate the boardfeet. Later, the board feet measurement is adjusted according to actualthicknesses. For example, if a group of 1/2" boards are being edged, thecomputer 66 will edge them assuming a 1" thickness and as each board isedged the board foot measurements are added together and stored inmemory. At the end of a run of 1/2" boards the total board footmeasurement is divided by two and, thus, the board foot measurement isadjusted to reflect actual thickness.

A block diagram of the edger 19 is shown in FIG. 6 to illustrate thecontrol interconnections of edger 19. The control panel 24 is interfacedwith the computer 66 which is interfaced with the operating systems ofthe edger 19 comprising the chain lifts 27, chain drives 84, the sawservo positioner 60, the trim markers 24, the feed roller drives 86, anda saw drive 88. The edger chamber 31 and the internal components arepreferrably Model E648 edgers produced by Corley Manufacturing Company.The saw servo positioner 60 is preferably a piston and cylinder set withan ultrasonic position transducer built within it such as manufacturedby Temposonic. The positioners 60 are connected by a mechanical linkage90 to the saws for adjusting the saw positions. Also, mechanicallinkages 92 are provided between the saws 32 and the lasers 34 so thatthe lasers 34 move with the saws, and the positioner 60 provides asignal to the computer 66 indicating the position of the saws 32 andlasers 34.

An alternate embodiment of the invention is shown in FIGS. 7, 8, 9, 10and 11 in which FIG. 7 is a plan view; FIG. 8 is an end view; and FIG. 9is a side view of an edging apparatus 100. FIG. 10 is block diagramillustrating the operation of the apparatus 100 and FIG. 11 is a blockdiagram illustrating control interconnections. Referring now to FIGS.7-11, it will be appreciated that the edging apparatus 100 includes apreview table 102 and an infeed table 104 that are positioned in aside-by-side parallel relationship. Boards are delivered to infeed table104 by chains 106 mounted on sprockets 108 and chains 110 that aremounted on and driven by sprockets 112 and 114. The chains 110 move theboards transversely across the preview table 102 until the boards engagestop pins 116. The stop pins 116 will align at least one edge of theboard in a direction generally parallel to the longitude of the previewtable 102 and perpendicular to the chains 110. The pins 116 are mountedon brackets 118 which are slidably keyed to support rods 120. The pins116 and bracket 118 are driven by servo positioners 117 to slide alongthe rods 120, and air cylinders 119 move the pins 116 up and down. Bothmovements are controlled by the operator through the control panel 124,and using pins 116 the skew of a board on the preview table 102 may beadjusted.

A longitudinal positioning fence 132 is provided to aid longitudinalpositioning of a board. The fence 132 is mounted on a piston andcylinder set 134 so that the maximum extended position of the piston andcylinder set 134 will place the fence 132 in a position defined as thefurthermost position for the end of the board. The operator controlsmovement of the fence 132 through the control panel 124 to place a boardin a desired longitudinal position.

A pair of lasers 136, mounted on the preview table 102, form laser lines138 which represent saw lines. The operator positions the laser lines138 on the board to select the lines along which the boards will beedged. The lasers 136 are laterally positionable by the operator usingthe control panel 124 and, preferably, a joy stick 128 is provided foruse in moving the lasers 136.

Referring to FIGS. 8 and 9, it will be appreciated that an array of trimlasers 140 and an end trim laser 142 are positioned adjacent infeedtable 102. The trim lasers 140 and 142 project lines across the previewtable 102 in a direction perpendicular to the longitude of the table 102and generally parallel to the chains 110 to show the operator standardlengths to which a board may be trimmed. The distances between each ofthe lasers 140 and the laser 142 are equal to the standard hardwoodboard lengths. By observing the laser lines projected by the lasers 140and 142, the operator adjusts the position of the board and chooses atrim length for the board. By reference to FIG. 9, it may be appreciatedthat the longitudinal adjustment fence 132 may be used to adjust the endposition of a board, and a board length is then fed into a computer 180by the operator through a key pad 126 on the control panel 124. In thismanner, the operator selects a trim length and positions the board forbeing appropriately marked for the trim.

Referring again to FIGS. 8 and 9, it will be noted that trim markers 144are aligned with the array of trim lasers 140 and 142. As best shown inFIG. 8 the trim markers 144 include marker wheels 146 mounted on theouter end of an arm 148 whose other end is pivotally mounted on a pin150 and vertical support member 147. A piston and cylinder set 153 isalso connected to the arm 148 to lift and lower the arm 148 and markerwheel 146. The piston and cylinder set 153 will normally hold the arm148 and wheel 146 in the position indicated by the dotted lines 154.However, when an operator selects a particular trim length, theappropriate one of the trim markers 144 will be lowered to the positionshown in FIG. 8. Thus, as a board passes between the preview table 102and the infeed table 104, it is marked for trimming. Since the end trimmarker 146 is always used to mark the end of the board, it alwaysassumes the position shown in FIG. 8. Also, as best shown in FIG. 9, itwill be noted that the end trim marker 146 is aligned with thelongitudinal adjustment fence 132 when the fence 132 is located in itsoutermost position.

Referring again to FIG. 7, the transfer of the boards from the previewtable 102 to the infeed table 104 is described. Once the operator hasselected the initial cut position by moving the lasers 136 to desiredpositions and with the aid of the computer 180 has selected best cutpositions, the command is given through a special purpose button 130, totransfer the board from the preview table 102 to the infeed table 104.When this command is received, the pins 116 are moved downwardly by aircylinder 119 to disengage the board and the positions of the lasers 136are stored in the computer 180 as the best cut positions. The chains 110are then lifted and driven to transfer the board toward the infeed table104. Once the board moves off of the preview table 102, it is picked upby chains 149 that are mounted on sprockets 151 and 155. As the board iscarried on the chains 149, the trim marks are placed on the board by oneof the trim markers 144 and the end trim marker 146 in accordance withthe trim length that was previously entered into the computer throughthe control panel 124. The boards then continue their travel and aretransferred onto chains 156 that are driven by and carried on sprockets158 and 160. The boards continue to travel across the infeed table 104until they engage the stop pins 162 that are mounted on brackets 164which in turn are mounted on rods 166. The pins 162, servo positioners163, brackets 164, air cylinders 165, and rods 166 are structured anddriven like pins 116, servo positioners 117, brackets 118, air cylinders119, and rods 120. The stop pins 162 are moved by the computer 180 toidentical positions relative to the infeed table 104 as were the pins116 relative to the preview table 102. Thus, when the board engages thestop pins 162, it is in a known position on the infeed table 104.

A saw chamber 168 is provided at the end of the infeed table 104, and apair of edging saws 170 are mounted within the chamber 168 in aconventional fashion. The saws 170 are movable in a transverse directionwith respect to the longitude of the infeed table 104 and, thus, may bemoved to adjust the edging of the board. Since the board will be in aknown position on the infeed table 104, the saws 170 may be placed inthe best cut positions that were previously selected by the operator.The operator chose the best cut positions using the lasers 136 and thesepositions were fed to the computer 180 shown in FIG. 10. When the boardis in proper position on the infeed table 104, the computer adjusts thepositions of the saws 170 to the best cut positions as previouslychosen. After the saws 170 are properly positioned and the board isproperly positioned on the infeed table 104, the board is fed into thesaw chamber 168.

In accordance with this embodiment, to feed a board, the chains 156 arelowered so that the boards rest on rollers 174 and the presser roller172 is forced against the upper surface of the board. Next, all of therollers 174 are rotatably driven to feed the board toward the saws 170,and the chamber 168 may also include feed rollers such as rollers 35shown in FIG. 2. Just before the feeding process begins, the pins 162are rotated downwardly by means of the brackets 164 and the rods 166 onwhich the pins are mounted. In this manner, the pins will not interferewith the movement of the board into the saw chamber 168.

Referring now to FIGS. 10 and 11 in conjunction with FIGS. 7, 8 and 9,the control of the edging apparatus 100 may be described in greaterdetail. The overall operation of the edging apparatus 100 is controlledthrough a computer 180. The computer 180 preferably receives its inputsthrough the control panel 164 or it may receive inputs through physicalmeasuring devices. For example, a mechanical foot can be used to measurethe thickness of the board as it passes onto the preview table 102.

The edging process begins when a board is fed onto the preview table 102in response to commands from the control panel 124. The board will moveacross the preview table 102 until it engages the stops 116. The stops116 are mounted on a bracket 118 that is keyed to a rod 120. The bracket118 will slide longitudinally on the rod 120 and it is positionedthereon by preposition servo positioners 182 (shown as 117 in FIG. 8).Thus, the positions of the pins 116 may be controlled by means of thepreposition servo positioners 182 through the control panel 124.Preferably, the joy stick 128 is selectively connected to control thepositions of the pins 116. Thus, by manipulating the joy stickpositioner 128, each of the pins 116 may be positioned and the skew of aboard on the infeed table 102 may be adjusted. The preposition servopositioners 182 are connected to the computer 180 and positioninformation is fed to the computer 180. Thus, the computer 180constantly monitors the positions of the pins 116.

Next, the joy stick positioner 128 is connected to control servopositioners 184 that are used to move the lasers 136. Each of the lasers136 is mounted for transverse movement which is controlled by a servopositioner 184. By manipulating the joy stick positioner 128, each ofthe lasers 136 may be positioned as desired. Again, the servopositioners 184 are connected to the computer to provide position data,and when the lasers 136 are positioned as desired in an initial cutposition, this position is recorded in the computer 180.

Next, a board thickness input 186 is provided to the computer 180 by theoperator through the control panel 124 using the key pad 126, but suchinput 186 may alternatively be provided to the computer 180automatically through a direct measuring device that actually measuresthe thickness of the board. Likewise, a board length input 188 isentered into the computer 180 by the operator using the key pad 126 onthe control panel 124. Also, a saw kerf adjustment input 190 and anoffset adjustment 192 are provided to the computer 180. These twoadjustment inputs are the same as inputs 80 and 82 described withrespect to the first embodiment shown in FIGS. 2-6. A compute command194 is provided to the computer 180 preferably through a special purposebutton 130. When the compute command 194 is given to the computer 180,it will calculate the best cut positions for the saws based on the boardthickness input 186, the board length input 188 and the initial cutpositions selected by the operator. The initial cut positions willnormally be the positions of the lasers 136 when the compute command 194is given. Upon receiving the compute command 194, the computer willchoose a best cut position and will provide a position output to theservo positioners 184 that will place the lasers 136 into the best cutpositions and will show the operator the positions that the computer hascalculated as the best cut positions. The compute command 194 will alsocause the computer 180 to store the final positions of pins 116 whichwill be used to set the positions of pins 162 on the infeed table 104.

Assuming the operator agrees with the best cut positions chosen by thecomputer 180, a transfer command 196 is given to the computer 180through the control panel 124, preferably using a special purpose button134. When the transfer command is given, the board is transferred fromthe preview table 102 to the infeed table 104. In response to thetransfer command 196, the computer generates a trim marker output 197that actuates an appropriate one of the trim markers 144 and marker 146which are forced downwardly onto the board to mark the selected trimlocation based on the board length input 188. Also, in response to thetransfer command 196, the pins 162 are adjusted by the computer 180 intoa position corresponding to the former positions of the pins 116. Thisadjustment is made through infeed servo positioners 200. Thus, when theboard stops on the infeed table 104, it will be in a positioncorresponding to its position on the preview table 102.

Each of the saws 170 has a separate servo positioner 198 so that thesaws 170 may be set to any desired position. The computer 180 will placethe saws 170 in the best cut positions that were selected on the previewtable 102. Since the position of the board on the infeed table 104 isknown to exactly correspond to its position on the preview table 102,the saws 170 are positioned so that they cut the board along the bestcut positions as shown by the laser lines 138 when the board was on thepreview table 102. After the board is properly positioned on the infeedtable 104, the press roller 172 engages the upper surface of the board,the rollers 174 are driven and the board is fed into the saws 170 foredging.

A manual override input 202 may also be input into the computer 180through one of the special purpose buttons 130. If a manual overrideinput 202 is chosen, the operator chooses the edging for the boardindependently of the computer. In this mode, the joy stick positioner128 is connected to control the servo positioners 184 for the lasers andselect a particular edging for the board. In the manual mode, when thetransfer command 196 is given, the saws 170 will be moved to theposition selected by the operator using the lasers 136. Also, when themanual override input 202 is given to the computer 180, the joy stickpositioner 128 may be connected to the servo positioners 198 for thesaws 170. Thus, after the board is positioned on the infeed table 104and the saws 170 have been moved by the computer 180 to the selectedpositions, the operator may, if he chooses, again move the saws 170 toanother selected position.

Sequence inputs 206 are also fed to the computer 180. These sequenceinputs 206 control the sequence of events when one command initiatesseveral actions. For example, the transfer command will cause the pins116 to move downwardly out of the way, will cause the chains 110 toengage and move the board, will cause the chains 149 to begin moving,will cause one of the trim markers 148 to move downwardly, will causethe chain 156 to begin moving, will cause the pins 162 to rotateupwardly and will cause the chains 156, 149 and 120 to stop moving afterthey have transferred the board to the desired location. The sequencingof these events is carried on in a conventional fashion through timingthat is built into the computer program and/or through mechanicalsensors such as limit switches or optical eyes, which may be placed inthe edging apparatus 100.

For clarity, the control interconnections are shown in FIG. 11. Thecontrol panel 124 is interfaced with a computer 180 which in turn isinterfaced with chain lifts 27, chain lift drives 210, saw servopositioners 198, preview skew positioners 182, infeed skew positioners200, laser servo positioners 184, infeed pin drives 212, preview pindrives 214, infeed roller drives 216, press roller drive 218, trimmarkers 144 and longitudinal positioning foot 132. The chain lifts 27shown in FIG. 11 collectively refer to the lift mechanisms used to liftchains 106, 110, 149 and 156. These lifts are essentially the same aslifts 27 shown in FIGS. 2-4. Likewise, the chain drives collectivelyrefer to motors that drive chains 106, 110, 149 and 156. The saw servopositioners 198, preview skew positioners 182, infeed skew positioners200 and laser servo positioners 184, are piston and cylinder sets havingposition transducers that are interfaced with the computer 180 forconstantly providing the computer 180 with the positions of themechanisms that are attached to the positioners. The infeed pin drives212 and the preview pin drives 214 collectively refer to the drivesystems for moving the pins 116 and 162 in both the transverse andvertical directions as previously described. The infeed roller drives216 represent motors that drive the rollers 174, and the press rollerdrive 218 refers to a piston and cylinder set that drives the pressroller 162 downwardly.

Having described the two foregoing embodiments of the present invention,it will be appreciated that the invention provides an edger that iscapable of edging boards taking into consideration the rounding ruleused in the hardwood lumber industry. That is, the edger of the presentinvention can take advantage of the rounding rule, can be neutral withrespect to the rounding rule, or can edge the boards so that therounding rule works to the disadvantage of a particular saw milloperator. Also, the present invention provides structure and controlthat allows the trim decision and the edging decision to be made at thesame time and by the same operator. In this manner, the trim decisionsand edging decisions may be made more intelligently. The operator mayconsider the length of the board when making his edging decision or hemay consider the edging decision when he makes the trim decision.Although particular embodiments have been described in the foregoingDetailed Description, it will be understood that the invention iscapable of numerous rearrangements, modifications and substitutions ofparts without departing from the scope of the invention as set forth inthe appended claims.

What is claimed is:
 1. An edging apparatus controlled by an operator andhaving saws for edging a board that is priced by the whole board foot inaccordance with a rounding rule, comprising:positioning apparatus forpositioning and holding the saws; selection means controlled by theoperator for selecting initial cut positions for the saws; input meansfor generating input data including board length and initial cutpositions; compute means responsive to the input data for at leastmultiplying the length data by a width factor corresponding to theinitial cut positions to produce a computed signal; output means foroutputting the computed signal; and means for positioning the saws basedon the computed signal.
 2. The apparatus of claim 1 wherein said computemeans further comprises means for producing a computed signal thatcorresponds to the product of the length data and width factor roundedin accordance with the rounding rules.
 3. The apparatus of claim 1wherein said output means further comprises display means for displayinginformation based, at least in part, on the computed signal.
 4. Theapparatus of claim 3 wherein said means for positioning comprises manualmeans for positioning the saws by an operator based on the informationshown on said display means.
 5. The apparatus of claim 1 wherein saidinput means for generating input data comprises, in part, a computermemory programmed to assume a one inch board thickness.